Maternal Obesity Elevates CRC Risk in Adult Offspring

Maternal obesity and trajectories of weight gain during pregnancy appear to increase the risk of colorectal cancer in adult offspring, suggest study findings published online ahead of print in Gut.

“Obesity is a well-established risk factor for colorectal cancer,” researchers wrote, “and fetal or developmental origins of obesity may underlie its effect on cancer in adulthood.”

The study investigated maternal obesity, pregnancy weight gain, birth weight, and colorectal cancer in adult offspring in a cohort of more than 18,000 mother-child dyads. The mothers were part of the Child Health and Development Studies from 1959 through 1966 in Oakland, California. Information was abstracted from mothers’ medical records at the time of pregnancy through delivery as well as the California Cancer Registry through 2019.

Maternal obesity more than doubled the risk of colorectal cancer in adult offspring, the study found. Researchers reported an adjusted hazard ratio of 2.51.

Similar increases in colorectal cancer risk occurred with trajectories of pregnancy weight gain. Specifically, risk increased when the rate of early pregnancy weight gain was discordant from total pregnancy weight gain—whether the early weight gain was higher, or lower, than total weight gain, researchers explained.

The study also identified an elevated colorectal cancer risk in offspring who weighed 4000 grams (8.82 pounds) or more at birth. However, researchers pointed out the association with colorectal cancer may be an independent one, since birth weight is related to but not redundant with maternal obesity and pregnancy weight gain.

Regardless, they believe the current prevalence of maternal obesity may lead to increasing rates of colorectal cancer in the future.

“Half of offspring diagnosed with colorectal cancer in our study were diagnosed younger than age 50 years,” researchers reported, “and our findings suggest maternal obesity and pregnancy weight gain may contribute to increasing incidence rates of colorectal cancer in younger (age <50 years) adults.”

—Jolynn Tumolo

Reference:

Murphy CC, Cirillo PM, Krigbaum NY, et al. Maternal obesity, pregnancy weight gain, and birth weight and risk of colorectal cancer. Gut. Published online ahead of print August 24, 2021.